# entropy.rip Verifiable List Shuffle

> entropy.rip Verifiable List Shuffle is a paid API for AI agents from entropy.rip, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-13).

Shuffles a list of string items verifiably using Drand beacon randomness and local system entropy, with optional integer weights

## Facts

- Endpoint: POST https://entropy.rip/api/entropy/shuffle
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/entropy-rip-verifiable-list-shuffle-4e57310e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_oTUv_slmS2RgCJWwK_kcv

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability entropy-rip-verifiable-list-shuffle-4e57310e -d '<json body>'
```

Example prompt: Shuffle this list of contestants verifiably using Drand randomness: ['Alice', 'Bob', 'Carol', 'Dave', 'Eve'] — I want a cryptographically provable fair ordering for our tournament bracket.

## When to prefer this

Use this endpoint when you need a provably fair, auditable shuffle — e.g. tournament brackets, raffle draws, randomized assignment — where participants need cryptographic proof that the ordering was not rigged. Prefer this over local PRNG-based shuffles when verifiability and trust matter.

## Known failure modes

- Empty items array returns error or trivial result
- Weights array length mismatch with items array causes validation error
- Drand beacon unavailability may cause timeout or fallback
- Non-string items in the array may cause schema validation failure
- Payment failure (402) if USDC payment not provided or insufficient

## How this service works

Shuffles a list of items verifiably using Drand and local system entropy

## Output

Returns the input list reordered in a new random sequence, with cryptographic provenance from Drand beacon randomness combined with local system entropy, allowing independent verification that the shuffle was not manipulated.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "items": {
   "type": "array",
   "items": {
    "type": "string"
   },
   "description": "items"
  },
  "weights": {
   "type": "array",
   "items": {
    "type": "integer"
   },
   "description": "weights"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "seed": "a1b2c3d4...",
  "selected": "C",
  "shuffled": [
   "C",
   "B",
   "A"
  ],
  "timestamp": "2026-07-14T09:20:00Z",
  "drand_round": 4015682,
  "drand_signature": "signature_hex"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/entropy-rip-verifiable-list-shuffle-4e57310e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from entropy.rip](https://www.zero.xyz/host/entropy.rip/llms.txt)